ONT ethernet port difficulties

[Xena451]

Lately my wireless internet has stopped working, necessitating 2 technician visits in the last month. I have internet without cable through the ethernet port on my ONT box, connected to a Netgear AC1200 router I bought myself. Whenever the internet cuts out I open the Netgear Genie and it tells me there is no ethernet cable connected when that is not the case. I've tried 4 different ethernet cables, 2 of which were provided by Verizon technicians and 2 of which are mine. When I directly connect my laptop to the ONT box I am not able to connect to the internet, which leads me to believe this is the box's fault, not the router's. As I said 2 technicians have come and replaced the ONT box, which also leads me to think it was not the router but the box.

My question is this- could it be an electrical issue with the outlet the box is connected to? I find it very unlikely that I could have been given 3 faulty ONT boxes by Verizon. The first tech just said he was getting "all kinds of error messages" from the box and replaced it, and the second tech said the first tech bent some wiring when installing the box. Both visits they have made sure the box works and I am then able to reset the router and gain internet, but it has been not even 24 hours since the last time the ONT box was replaced and my internet is gone again. 

I am getting very frustrated! I seems like more work than it's worth to keep paying Verizon for internet that doesn't even work. At this point I would be happy to find out that the problem is something silly related to a power surge, or an incompatible wifi router. But how can I tell these things??

Please help me! I just want my internet back!

[Edg1]

Are there any changes to the lights on the ONT when the internet goes down? Does the link light on the ethernet port of ONT go off?

It could be the power adapter or the wire from it to the ONT. Were either of those changed from the tech visits? Or just the ONT?